The Best Urban Gardening Method You’re Not Using

It’s a hot, bright Thursday night, and more than 40 people are gathered on folding chairs inside the Gowanus Studio Space. A mix of ages, they are all here to listen to Bob Hyland, a 75-year-old expert in what he calls urban “greenscaping.” Some work in the industry, such as a a landscape architect and a carpenter who specializes in planters; some are home gardeners; a few traveled as far as Philadelphia. With sweat blossoming through his polo shirt and dripping down his brow, Hyland tells his rapt audience, “There has never been a better time or opportunity. I don’t know of a more wide-open field.”

He’s talking about Sub-Irrigated Planters (SIPs), which Hyland explains is more of a system than a planter. “It’s nothing more than plumbing,” he says. Also known as a self-watering container, SIPs provide edible and decorative plants even, constant “sips” of water through a reservoir placed at the bottom of its roots. Using SIPs, an estimated 90 percent of water is conserved compared with overhead watering, and they eliminate the risk of groundwater pollution or contaminants in in-ground soil, a big concern in cities. As a result, plants are much more productive and healthier than other gardening systems, even in-ground. Think of it: instead of washing away nutrients in the soil as you water from above, the plants are constantly taking in nutrient-rich water from beneath. SIPs are also portable; if you green an abandoned lot that’s ultimately sold, or you move, you can take your garden with you.

Frieda Lim is a convert. Two seasons ago, she almost designed Slippery Slope Farm, a 225-square-foot garden on her Gowanus rooftop, using a classic, raised bed drip irrigation system. Then she discovered SIPs on Hyland’s blog, insideurbangreen.org, and learned that he lived in Brooklyn. “I completely lucked out with Bob, whom I refer to as the man guarding the Holy Grail. He has been by mentor since day one.” This summer her 75 SIPs–many of which she waters just once or twice a week–have yielded a mountain of produce including 12 varieties of tomatoes (some as high as six feet), eight kinds of peppers, four types of beans, cucumbers, eggplant, burgandy okra, Asian greens, and some of Thursday night’s refreshments: Lemon basil-infused ice water, lovage syrup with seltzer, and goji berries. She says she was inspired by Hyland to use SIPs because it just makes more sense in an urban environment: “No offense to all the urban gardens that have taken root on rooftops and empty lots, but given the challenges of urban living and climate change, why are most people farming as if they were still in the country?”

Hyland’s gardening experience has always been heavily rooted in cities. After a prior career in technology with IBM, he’s spent the past 35 years trying to find modern solutions for growing and maintaining plants in the built environment. He studied landscape architecture and horticulture at Cal Poly Graduate School of Environmental Design, then ran a prominent interior plantscaping company in Los Angeles, where he was first introduced to SIPs. Now he lives in Bay Ridge, and last year, he founded the Center for Urban Greenscaping (CuGreen) to educate and motivate the uninitiated to sub-irrigated planting. Its temporary home is his blog, though a physical center is the goal. In the meantime he plans to hold a series of in-person workshops like the one last Thursday at GSS.

Custom-built SIPs

SIPs systems come with their downfalls, as Hyland notes, which include a lesser use of compost and higher initial set-up costs. There are readymade SIPs, like EarthBox (which start at $30), though Hyland also suggests DIY solutions on his site that can be built for under $10. Using plastic for planters is a concern, but contaminated soil is an even greater threat, and the most affordable SIPs can be made with food-grade plastic containers, HDPE 2 and PET. (Frieda Lim also uses lead-free water hoses.) The unsightly plastic containers themselves are a common stigma for SIPs, though more attractive sub-irrigated raised beds are arriving on the market. Already Hyland and Lim have experimented with wood-framed beds at Liberty Sunset Garden Center (pictured above and below), and with the help of designers and architects like her husband and her sister, Lim is working on sleeker designs herself. She also offers design services for SIPs gardeners.

Hyland urges others to innovate with planting methods. For a man who grew up in the era of postwar Victory Gardens, he finds the lack of experimentation among today’s urban gardeners frustrating. “Why are we not taking the challenge in the area of personal food production?” he asked his audience last week. More than a few stared back with blank expressions. Sometimes it takes time for a revolution to grow.

Look out for future SIPs workshops on InsideUrbanGreen.org, where Bob blogs about his discoveries and reflections on modern greenscaping. And listen to an interview with Frieda and Bob on the Heritage Radio show, “Let’s Eat In,” hosted by Cathy Erway, an urban gardener who tends to Sixpoint’s rooftop farm in Red Hook. She doesn’t use SIPs yet, but plans to.